Motorists tipped to pay 3c/l more

AUSTRALIAN motorists can expect to pay up to three cents a litre more for petrol in the next 10 days as a better outlook for the global economy spurs demand for oil.

CommSec economist Savanth Sebastian said the key Singapore unleaded price rose by $A5.60 over the past fortnight to a four-month high.

"The main driver behind the gains in regional oil prices has been the better global economic data and improvement in investor risk appetite - fuelling the demand for commodities like oil," he said in an investor note on Tuesday.

CommSec forecasts the national pump price will rise by three cents a litre in the next seven to 10 days.

The Australian Institute of Petroleum released data on Tuesday showing the average national unleaded petrol price was unchanged at 141.9 cents a litre last week.

The metropolitan price rose by 0.2 cents to 140.2 cents a litre, while the regional average price fell by 0.4 cents a litre to 145.4 cents a litre.

Sydney had the cheapest average unleaded fuel, down 0.9 cents at 137.4 cents a litre, while Darwin was the dearest, unchanged at 159.1 cents a litre.